Oh wow, loved your other diorama but I think I like this one even more! I really like how you've got everything smooshed in there- it really does give the feel of a narrow choke-point used to hold off a foe.
And as usual I love the looks of the vehicles and the overall positioning of the debris. They look the part of burnt-out wrecks and a jumble of stuff piled up to make a blockade.